Method of producing articles of hadfield manganese steel



Ergo sraras or ies METHOD OF PRODUCING ARTICLES OF HADFIELD MANGANESE STEEL Elmer B. Welch, McKeesport, Pa... assignor to Firth-Sterling Steel Company, McKeespoi-t, Pa, a corporation of Pennsylvania No Drawing. Application March 31, 1937,

. Serial No. 134,189

3 Glaims. (Cl. 75-22) This invention relates to the production of then charged into a suitable mold or die and shaped articles of Hadfleld manganese'steel, and subjected to a pressure of the order of 2000 consists of a method of procedure whereby artipounds to the square inch and upward. Under cles of this material may be prepared most eco- Such pressure the body becomes coherent. The

5 nomically. shaped and coherent body is then removed from 5 Hadfield manganese steel is a steel having a the mold; it is then packed in finely divided manganese content that. ranges from '7 to 20 per alundum or equivalent refractory material, withcent. and a carbon content of 0.47-2%, and typiin a suitable tube or boat of carbon or other recally has a non-ferrous composition of combined fractory; and, so packed, it is brought within a 0 carbon, 1.15%; silicon, 0.551%; manganese, furnace whose atmosphere is an atmosphere of 13.733%; sulphur, 0.043%; phosphorus, 0.091%. hydrogen or other reducing gas to a tempera- (See Harbord 8: Hall, Metallurgy of Steel, 4 ed. ture of 1500-2000 F. Under such conditions a London, 1911, pp. 392-394.) This, as the authors coalescence or sintering of the compacted macited say, was, when Hadfield first produced it terial occurs. Alloying, however, does not occur.

"for all practical purposes, a new metal. It '-When by such procedure the-substance of the Hit possesses very peculiar hardness both in the shaped and coherent but granular article has cast and forged state, and it is scarcely possible been caused to coalesce, the article is taken from to machine it. Because of its relatively great the furnace, allowed to cool. and is then removed hardness, fabrication of particular articles is diffrom its packing.

o flcult, and on that account its use for certain The article is now in the form of a block or all articles, for which otherwise it is well suited, has brick, and has acquired the condition of integrity,

been practically inhibited. An instance is found as distingu s ed from granular condition All inthe case of a bit for the drilling of wells. Hadalloying of thecomponent metals has not, howfield manganese steel has properties such that a ever, yet occurred. In such condition of integrity bit formed of it must manifestly be peculiarly the article may readily be machined. and it is 25 serviceable; but the cost of fabrication has been then by appropriate tools brought to the desired suchas to diminish, if not completely to destroy, ultimate shape. It may at this time and in such its availability here. In the practice of this incondition be otherwise shaped, as by forging, vention shaped articles (of which abit for drillrolling, or die-pressing. In whatever way the ing wells may be taken as typical) of Hadfleld shaping be done, the shaped article is packed so manganese steel may be cheaply produced. again as before in a tube or boat, placed again According to preferred procedure, a quantity in a reducing furnace, and heated, this time to of iron powder is prepared, and a quantity of the higher temperature of 2250-2650 F., short of manganese powder or of ferro-manganese powthe m n -p in 0f irOn- At uch higher e der, and these two powders are combined in such perature the component metals combine to form 5 ratio as to afford the desired ratio of iron to the intended alloy. Th Shape, however, manganese in the finished product (typically tinues. When thereafter the article is removed 87:13). Care is taken that the carbon content from the furnace. cooled, and taken from its of the combined powder shall be within the typipackin it will be found to be the desired article- 40 cal range (and this, for the iron-manganese ratio the shaped article of Hadfleld manganese steel. 40 just given, will not greatly exceed 1%) To such The detailed procedure that has been described end, the iron that is reduced to powder will prefis that which I have found to be practical in the erably be, relatively speaking, carbon free, and production of such an article as a bit for drilling the carbon content of the manganese or ferrowe ls. for example.

manganese will be properly limited. While pref- Instead of beginning with the iron and the 45 erably the iron powder will be substantially free manganese in metallic state, I contemplate also of carbon it is permissible to employ a powder the preparation of a pulverized mixture of the having an appreciable carbon content; but in oxides of these metals. together with carbon in such case the carbon content of the manganese properly measured quantity; heating the pre- (or term-manganese) powder will be such as to pared mixture to substantially 1800" R, where- 50 afford in the ultimate product no more than the upon theoxldes willbe reduced; and then prodesired carbon content. ceeding by heat and pressure in such manner as When the two quantities of powder have been has already been described, with the result that brought together they are intimately and thora shaped article of Hadfleld manganese steel is 5 oughly mixed. The body of mixed powder is produced.

It is permissible to enjoy the invention and to produce a manganese steel, modified by additions up to 20% of one or more of the metals molybdenum, tungsten, chromium, and vanadium; and in such case the appropriate modifying metal, or its carbide, may, in pulverized condition, be included in the initial mixture.

In the ensuing claims I mean to include within the meaning of the terms iron-containing powder and manganese-containing powder powders of substantially pure iron and of substantially pure manganese, as well as powders of iron oxide, of manganese oxide, and of term-manganese; and I mean to include within the meaning of the term manganese powder powders both of substantially pure manganese and of ferro-manganese.

I claim as my invention:

1. The method herein described of producing. a shaped article of Hadfield manganese steel which consists in efiecting intimate mixture of iron-containing and manganese-containing pow- (lets, the manganese constituent being 7-20% of the combined metals, effecting under pressure coherence of particles, subjecting the pressed and coherent body while in reducing atmosphere to a temperature of 1500-2000 F. and in so doing effecting coalescence while the particles continue -in unalloyed state, shaping the cold body, and

subjecting the shaped body while in reducing atmosphere to a temperature of 2250-2650 F. and in so doing effecting alloying of the particles within the article of unchanged shape.

2. The method herein described of producing a shaped article of Hadfield manganese steel which consists in effecting intimate mixture of .within the article of unchanged shape.

3. The method herein described of producing a shaped article of Hadfield manganese steel which consists in eiiecting intimate mixture of iron-containing and manganese-containing powders, the manganese constituent being 7-20% of the combined metals, effecting under pressure coherence of particles, subjecting the pressed and coherent body while in reducing atmosphere to a temperature of 1500-2000 F. and in so doing effecting coalescence while the particles continue in unalloyed state, cooling the body, ma-

chining the cold body, subjecting the machined body while in reducing atmosphere to a temperature of 2250-2650 F. and in so doing effecting alloying of the particles within the article of un changed shape.

ELMER B. WELCH. 

